Manufacture of staple fiber



Patented Apr. 21, 1936 PATENT OFFICE MANUFACTURE OF STAPLE FIBER William Ivan Taylor, Spondon, near Derby, England, assignor to Celanese Corporation of America, a corporation of Delaware No Drawing. Application May 25, 1932, Serial No. 613,561. In Great Britain July 29, 1931 Claims.

This invention relates to the operation of producing staple fibers from continuous filaments, whether natural or artificial, for example filaments of natural silk and artificial filaments of 5 cellulose acetate or other cellulose derivatives or of reconstituted cellulose, such as viscose, cuprammonium and nitrocellulose silk.

The object of the invention is to facilitate the severing of continuous filaments into staple fiber,

0 not only asregards the actual cutting operation, but also the handling of the filaments before cutting and of the fibers after they have been cut.

According to the invention the filaments are 1"5' severed while wet, and preferably in thick bundles. The filaments should be laid parallel or substantially so in the bundles, so as to ensure aregular length of cut staple. Further, it is preferred to arrange the filaments so compactly in the bundles that though the wetting liquid is present in the bundles to a substantial degree there is no free liquid tending to separate from the bundles during the cutting operation, so that handling of the filament bundles and cutting can proceed without any inconvenience due to the presence of excess liquid.

It has been found that with bundles of filamentswetted in this way the filaments remain in'a compact condition convenient for handling both before and after cutting, and that the cutting can take place in a generally advantageous method without any possibility of loose filaments separating from the mass and interfering with the cutting or other'apparatus employed. The

wetting of the filament bundle gives the bundle a firmness and solidity which greatly facilitate cutting, while the liquid may act as a lubricant to ease the passage of the cutting blade through the filaments.

4O Conveniently the filament bundles are formed from hanks which can be cut to form a bundle having a length equal to the periphery of the hank and suitable for passage through a guillotine or like cutter. The hanks are preferably formed by parallel winding so as to give the most compact arrangement possible to the filaments in the bundle, and though the hanks'may be wound on a swift or reel, it is preferred to wind them on a smooth cylindrical drum 'so that the bundle of filaments when severed from the drum is capable of lying fiat without kinks. In this way considerable regularity in the length of staple out can be obtained.

Though the wetting of the filament bundles may take place after severance of a bundle from are cut on the drum or the like. 10"

The presence of the liquid enables the filaments to form a solid mass which can be readily handled, though it is convenient to effect the removal of the filaments from the drum or the like after severance with the minimum of handling. For example after the bundle is cut through, the drum or the like may be rolled along a suitable support so that the bundle is left lying on the support in a fiat condition without any kinks and without any separation of individual filaments or groups of filaments.

The thus wetted bundle may be allowed to stand for some time if desired until the required content of liquid is reached, which content is preferably of the order of on the weight of the filaments. In general, however, mere draining of the bundle on the drum or the like suffices to bring the content of liquid to the required amount. The bundle is then in a suitable condition for cutting. 30

The cutting may be effected by any suitable means. For example, the bundle of filaments may be fed endwise to a reciprocating cutter, the feed of the filaments and the frequency of out being adjusted in accordance with the length of staple 35 required. By the use of a suitable conveyor belt or the like cutting may be carried out as a continuous operation by placing bundles end to end and feeding them at a constant rate to the cutter blade. The severed filaments form compact 40 masses having no tendency for the separation of individual fibers, and these masses may be collected in a suitable container near the cutting blade. It is, however, convenient to allow the fibers to fall on to a further conveyor where fibers of short length, such as may be formed in cutting the ends of the bundles, may be readily detected and separated from the remainder.

It is, of course, important to remove the bulk of the moisture contained in the masses of fibers 0 before the subsequent spinning operation, and for this purpose any suitable drying operation may be employed. For example the fibers maybe placed in trays or other suitable containers or conveyors and allowed to dry ither in the open air orwith the assistance of suitable accelerating means such as heat, drying currents or in a vacuum, or by any desired combination of these means. The drying operation referred to above may be preceded by a preliminary centrifuging operation, adapted to reduce the liquid on the yarn from, say 100%, which is the figure most convenient in the cutting operation, to 35-40%.

Before carding the fibers it may be found desirable to pass them once or more through an opener in order to break up the masses of fibers resulting from the cutting operation, after which opening operation the fibers are passed to a scutcher, which forms them into a lap for card- In order further to facilitate the conversion of the fibers into spun yarns, they may, at any suitable stage, preferably before the bundles of filaments are cut up, be subjected to a crinkling operation. For this purpose, the length of filament, prior to cutting, may be subjected to a boiling or steaming treatment in suitable baths or ovens, or to a chemical crinkling operation, as described for example in U. S. Patent No. 1,554,801.

The winding of the filament bundles may take place in any suitable textile operation. For example filaments or threads of twisted or untwisted filaments may be led from a package or preferably from a number of packages to the drum or the like on which the bundles are wound in hank form, the drum being of a width appropriate to the width of bundle capable of being passed through the cutting machine. The drum may, however, be of greater width, either for the reception of a plurality of hanks each forming a separate bundle or for the reception of a wide hank which may be subdivided, preferably after cutting from the drum or the like, into two or more bundles of suitable width.

The winding operation described above is particularly suitable for use with waste yarns which it is desired to convert into staple fiber. Winding may, however, take place continuously with the production of artificial filaments, and for this purpose any desired number of filaments may be led continuously with their production in a spinning machine to a drum or the like and wound into bundles in the manner above described. In this case the drum may be driven at a peripheral speed corresponding to the rate of production of the filaments, and the drum may be arranged to draw the filaments directly from the spinning jet so that the denier of the filaments is governed by the peripheral speed of the drum. In order to ensure that there is little denier variation in the filaments thus produced, winding should cease before the increased peripheral speed due to the increasing diameter of the surface on which the filaments are received on the drum exceeds the peripheral speed of the drum itself by, say, two or three per cent.

Though, as stated above, the drum may draw the filaments directly from the spinning jet, a feed roller driven at an appropriate peripheral speed may be interposed between the drum and the jet so that the feed roller determines the denier of the filaments and the drum merely acts as a collecting device.

This method of collection continuously with the production of artificial filaments is particularly applicable to the collection of filaments of cellulose acetate or other cellulose derivatives produced by the dry-spinning method. For example one drum may be arranged to receive the filaments from say six spinning jets of the dryspinning apparatus by the provision of guides to lead the several bundles of filaments to the drum or the like, a traversing guide being employed to lay the filaments over the required width. In order to ensure continuity of winding, two drums may be provided so that on completion of a hank on one drum the filament bundle may be transferred to the other drum on which winding proceeds during removal or wetting and removal of the filaments on the first drum. The drums are suitably arranged'to be removed out of engagement with the belt or other driving gear by which they are driven and to be lifted from their bearings for removal of the hank.

The drum provided for reception of the filaments may be formed with a slot in its periphery as described in British Patent No. 357,565, for the passage and. guiding of the knife used for cutting the filaments.

Any wetting liquid may be employed which has no deleterious action on the filaments, water being particularly suitable for the purpose. The liquid may, if desired, contain a proportion of wetting agent, e. g. Turkey red oil or other sulphonated oil, which assists the penetration of the liquid into the mass of filaments. Further, the wetting liquid may, if desired, contain substances adapted to facilitate the subsequent treatment of the fibers. For example, as described in British Patent No. 387,003, the wetting liquid may contain hygroscopic bodies in suitable concentration, which bodies remain on the fibers after drying and facilitate the carding and drawing and other spinning operations employed in converting the fibers into spun yarns. Again, fugitive colouring matter may be added to the wetting liquid in order to enable filaments or fibers of particular materials or deniers to be identified during subsequent treatments.

For convenience in handling and transport, the bundles may be rolled from the drum or the like on to a board or tray of suitable size. Several bundles may be placed on each board or tray until a suitable weight of filaments has been collected, the bundles being separated if desired by strips of paper or the like.

What I claim and desire to secure by Letters Patent is:-

1. Process for the production of staple fibers from continuous filaments of cellulose acetate or other organic derivative of cellulose, comprising applying a liquid containing a wetting agent to bundles formed from continuous filaments and cutting the thus wetted bundles of filaments into staple fiber.

2. Process for the production of staple fibers from continuous filaments of cellulose acetate or other organic derivative of cellulose, comprising applying a liquid containing a sulphonated oil to bundles formed from continuous filaments and cutting the thus wetted bundles of filaments into staple fibers. v

3. Process for the production of staple fibers from continuous filaments of cellulose acetate or other organic derivatives of cellulose, comprising applying a liquid containing a wetting agent to an assembly of continuous filaments, cutting the thus wetted filaments to form a bundle of filaments, and cutting said bundle into staple fiber.

4. Process for the production of staple fibers from continuous filaments of cellulose acetate or other organic derivatives of cellulose, comprising applying a liquid containing a sulphonated oil to an assembly of continuous filaments, cutting the thus wetted filaments to form a bundle of filaments, and cutting said bundle into staple fiber.

5. Process for the production of staple fibers from continuous filaments, comprising forming continuous filaments of organic derivatives of cellulose into a hank, applying a liquid containing a sulphonated oil to said filaments during the formation of the hank, cutting the thus Wetted hank to form a bundle of filaments, and cutting said bundle of filaments into staple fiber.

WILLIAM IVAN TAYLOR. 

